Study: Time In Range and Glucose Variability correlate with diabetic retinopathy for T2Ds independently of A1c

This interesting study out of China studies a population of Type 2 People with Diabetes PWDs), 24% of which have diabetic retinopathy:

The interesting conclusion appears to be (the whole article is unfortunately not available) that Time in Range and Glucose Variability correlate with advanced retinopathy, independently of A1c.

The senior lead author, Weiping Jia, out of China, has a solid publication trail.

Here is some more info at Reuters about the study:

[EDIT: Corrected for Sam]


So does it actually say “time in range and variability and ‘not a1c’” correlate with retinopathy

Or does it say that after adjusting for A1C, TIR and variability are correlated with retinopathy? Those would seem to mean completely different things to me… but I’m just on a tiny iPhone so I can’t evaluate it all that thoroughly

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The overall prevalence of DR was 23.9% (mild NPDR 10.9%, moderate NPDR 6.1%, VTDR 6.9%). Patients with more advanced DR had significantly less TIR and higher measures of GV (all P for trend <0.01). The prevalence of DR on the basis of severity decreased with ascending TIR quartiles (all P for trend <0.001), and the severity of DR was inversely correlated with TIR quartiles ( r = −0.147; P < 0.001). Multinomial logistic regression revealed significant associations between TIR and all stages of DR (mild NPDR, P = 0.018; moderate NPDR, P = 0.014; VTDR, P = 0.019) after controlling for age, sex, BMI, diabetes duration, blood pressure, lipid profile, and HbA1c. Further adjustment of GV metrics partially attenuated these associations, although the link between TIR and the presence of any DR remained significant.

CONCLUSIONS TIR assessed by CGM is associated with DR in type 2 diabetes.

Yes. I don’t see anything there that says or even implies that it was not correlated with A1c and only with TIR and variability. Actually I see that they had to control for A1C to even get to a level playing field to determine if TIR and variability were correlated, thus I think the topic of this thread is misleading… am I missing something?

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So you’re stating that this research is saying that A1C is not correlated with diabetic retinopathy and only time in range and variability are?

The particular conclusion that you just reposted to further make this point would also mean that duration of time with diabetes was also not correlated with retinopathy, correct? Because it was controlled for in the experiment just like a1c was in order to arrive at the conclusion that variability and TIR were correlated with retinopathy?

Just want to see how far you’re willing to take it…

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This link between time spent in range and eye disease was independent of the A1c readings, suggesting that even among people whose average blood sugar over months seems good, sharp daily fluctuations can still do damage.

Yes^ this is correct. But that doesn’t mean that TIR and variability and ‘not a1c’ are correlated with retinopathy

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The title of this thread is silly.

I’ll bet if you have really great time in range, your A1C will also be great.

In fact, I will challenge anyone to have really great time in range, and still have a crappy A1C.

If your range is something in the normal ballpark, like 80-120, and you spend most of your time there, Shazam! You will have a great A1C too!

And then you can say your lack of complications was from time in range, and A1C had nothing to do with it. :roll_eyes:

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Even aside from the two meaning essentially the same thing, as you point out… The study had to adjust for different a1c…
In other words “OF COURSE higher a1c means more retinopathy, so we had to statistically cancel our that known variable in order to meaningfully compare results of variability independently “

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If they were the same, then TIR would not correlate to retinopathy after being adjusted for A1c. That would be impossible.

This is why it is significant. According to this study, the same TIR correlates to the same odds of retinopathy at any A1c (corrected for the influence of A1c). That is quite unexpected.

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You probably can’t have a great TIR (assuming you’re picking a good, tight range, which not everyone does) and a terrible A1c. But you can have a great A1c and a terrible TIR.


I don’t see that stated. The stated result is that time in range/glucose variability is an independent risk for retinopathy. That means you get comparatively higher retinopathy risk if you have increased BG variability/time out of range, whether or not you maintain a good A1C.

Independent just means they are separate risk factors. One risk factor could theoretically moderate another, but more typically they kind of multiply. Like if you smoke and you breathe asbestos it’s much worse than either one alone.

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Yeah… the wording is corrected now and is now accurate

I had missed that. Glad it got straightened out and sorry for barking up the wrong tree.

Interesting article about relationship between a1c and TIR.

As a Medtronic user, I’d just have to throw in that TIR based on my CGM is deceiving.